What is an unhealthy weight?
Weighing too much or too little can be unhealthy and, in some cases, life threatening. Looking at weight on its own, however, can be misleading; weighing 75kg (about 11.5 stone) may be fine if you are 6 feet tall, but unhealthy if you are 5 feet tall. To work out a healthy weight according to your height, the Body Mass Index (BMI) must be worked out.
What is the Body Mass Index (BMI)?
The BMI is a way of telling if your weight is in a healthy range for someone of your height. It is worked out by dividing your weight in kg by your height in metres squared.
So, if you weigh 75kg and are 1.8m tall, then your BMI is: 75/(1.8x1.8) = 23.15
If you weigh 75kg and are 1.5m tall, then your BMI is: 75/(1.5x1.5) = 33.3
What is considered a healthy BMI?
So, once you have worked out your BMI, we now need to know if the number is healthy or not. As a guide, the ranges are:
|BMI less than 15
|BMI over 30
These numbers are for average normal adults, and do not apply to children or pregnant women. The BMI also does not differentiate between men and women, and can be misleading in athletes (eg a professional boxer may have a high BMI, but due to a large amount of muscle and not fat). For this reason, the BMI should be used as a guide only.
Why is it important to be in the 'normal range'?
Being either overweight or underweight can have serious health consequences. Malnourishment can lead to problems such as dry skin, hair loss, gum disease and irregular periods. Being overweight carries risks such as increased heart disease, breathing problems and developing diabetes. Being very overweight or underweight can even lead to early death.
How do I get into the 'normal range'?
The simplest way to understand weight loss or gain is in the form of calories. Even if we do no exercise whatsoever, we still burn off calories. These calories are used to fuel functions such as breathing, heart activity and brain function. The use of calories for basic life functions is known as the Basal Metabolic Rate (BMR) and will vary from person to person, but can account for up to 75% of the total energy used by the body.The rest of the energy is used up when walking, working, etc.
So, to gain weight, the obvious step is to increase the amount of calories going into the body. This can be in the form of high calorie shakes, or larger, regular portions of healthy food. Occasionally excessive exercise can lead to being severely underweight, and the obvious step in this instance is to reduce the amount of exercise taken. In athletes, weight is kept up by eating large amounts of calories - up to 10,000 more calories per day to keep weight stable!
To lose weight, the number of calories eaten per day can firstly be reduced. Whilst this in itself will help to start the weight loss process, the loss will soon tend to slow down. This is because the body senses that less food is available, and so begins to compensate for this by lowering the BMR. Now, because the BMR accounts for up to 75% of energy use, this lowering of BMR results in much less calories being burned off. The main way to combat this is to keep the BMR high or even raise it whilst reducing calorie intake. Increasing exercise will not only burn more calories but also increase lean muscle mass, which tends to raise the BMR. The exercise can be in the form of walking, swimming, running or anything you like - the trick is to start slowly and increase exercise gradually.
Most importantly, you need to be patient - trying to gain or lose weight too quickly can lead to disappointment and a 'rebound' effect, or can even have serious health risks. If you cut down on the amount of unhealthy food such as chips and fried food, and instead eat more healthy food and increase your exercise, then the weight loss should soon follow. And you will feel much healthier too!
In all cases, you should speak to your family doctor before undertaking any new diet or exercise regime.
Which diet plan is the best one?
There are a large number of diet plans available, and many will claim to produce quick and effortless results. Whilst some may work well and give long-lasting results, other diet plans may in fact be unhealthy or even dangerous. For this reason it is important to discuss any diet plan with your family doctor or a dietician to work out which diet method is best for you.
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The information provided is as a guide only. If you have concerns about your weight, you should consult your family doctor or a dietician. Please also read our disclaimer